Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Humans have many ...

For the most part, your organs and limbs serve a purpose, so it stands to reason that losing one of these can interfere with your body’s normal, everyday function. On the other hand, it’s well-known ...

The Conversation is asking kids to send in questions they'd like an expert to answer. Kristin, age 11, wants to know why animals have tails. An expert explains. Scientists have found fossils of ...